function prevNext(count,koniec,stan){
    $("#slider div.item").removeClass("active").removeClass("prev").removeClass("next");
        var next = count + 1;
        if(next > koniec){
            next = 0;
        }
        var prev = count - 1;
        if(prev < 0){
            prev = koniec;
        }  

        $("#slider div.item").css({"top":"0","left":"-1000px"})
        $("#slider div.item:eq("+prev+")").addClass("prev").css({"left":"-1000px"})
        $("#slider div.item:eq("+next+")").addClass("next").css({"left":"1000px"});
        $("#slider div.item:eq("+count+")").addClass("active").css({"left":"0px"});
        $("#arrow-change span").addClass("free").removeClass("busy");
        
        
}

function przesunWprawo(count,koniec){
    $("#slider div.item.active").animate({left: '-=1000'}, 1500);
    $("#slider div.item.next").animate({left: '-=1000'}, 1500);
    $("#slider div.item.prev").animate({left: '+=0'}, 1500,
    function(){
        prevNext(count,koniec,0)
    });

}

function przesunWlewo(count,koniec){
    $("#slider div.item.active").animate({left: '+=1000'}, 1500);
    $("#slider div.item.next").animate({left: '-=0'}, 1500);
    $("#slider div.item.prev").animate({left: '+=1000'}, 1500,
    function(){
        prevNext(count,koniec,1)
    });

}

function change(stan){
    var koniec = $("#slider div.item").size() - 1;
    var count = $("#slider div.active").index();
    if(stan == "next"){
        count = count + 1;
        if(count > koniec){
            count = 0;
        }
        przesunWprawo(count,koniec);
    }else{
        count = count - 1;
        if(count < 0){
            count = koniec;
        }
       przesunWlewo(count,koniec)
   }
}


$(document).ready(function(){ 
    
    var koniec = $("#slider div.item").size() - 1;
    prevNext(0,koniec,2);
    var refreshIntervalId = setInterval(function(){change("next")}, 7000);
    
    $("#arrow-change span").click(function(){
           if($(this).hasClass("free")){
               $(this).addClass("busy").removeClass("free");
               change($(this).attr("id"))
               }
               clearInterval(refreshIntervalId);
               refreshIntervalId = setInterval(function(){change("next")}, 7000);
           });
});